H-mode energy confinement scaling from the DIII-D and JET tokamaksFunded under: FP2-FUSION 10C
Neutral beam heated H-mode DIII-D and JET expanded boundary divertor discharges are examined, to study the parametric dependence of thermal energy confinement on plasma current, plasma size and neutral beam power. The single-null discharges in both machines are examined during the ELM-free phase in order to extract information about the intrinsic H-mode thermal energy confinement. A power law dependence of ELM-free thermal energy confinement is assumed. The size dependence of t(th) is described by the linear dimension L, since the determination of the individual a and R dependencies is precluded by the similar aspect ratio of the two machines. For this representation of t(th) with units of MA, MW and metres, when L is the plasma major radius C=0.106+/-0.011 and when L is the plasma minor radius C=0.441+/-0.044. A dimensionally correct version of the scaling, consistent with the constraints of a collisional high beta model, gives values within error bars of all coefficients with respect to the previously mentioned empirical scaling.
Bibliographic Reference: Report: JET-P(90)16 EN (1990) 31 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199011477 / Last updated on: 1994-12-02
Original language: en
Available languages: en